The glucanosyltransferase Gas1 functions in transcriptional silencing.

ABSTRACT: Transcriptional silencing is a crucial process that is mediated through chromatin structure. The histone deacetylase Sir2 silences genomic regions that include telomeres, ribosomal DNA (rDNA) and the cryptic mating-type loci. Here, we report an unsuspected role for the enzyme Gas1 in locus-specific transcriptional silencing. GAS1 encodes a beta-1,3-glucanosyltransferase previously characterized for its role in cell wall biogenesis. In gas1 mutants, telomeric silencing is defective and rDNA silencing is enhanced. We show that the catalytic activity of Gas1 is required for normal silencing, and that Gas1's role in silencing is distinct from its role in cell wall biogenesis. Established hallmarks of silent chromatin, such as Sir2 and Sir3 binding, H4K16 deacetylation, and H3K56 deacetylation,

SUBMITTER: Koch MR 

PROVIDER: S-EPMC2708717 | biostudies-literature | 2009 Jul

REPOSITORIES: biostudies-literature